Steering shaft, gear shift lever switch assembly

ABSTRACT

A rotary switch arrangement may be associated with an automatic gear selector mechanism to inhibit operation of the engine starting circuit at certain positions of the mechanism and at other positions to operate reversing lights and a seat belt warning system. The switch arrangement comprises a plurality of rotary members urged axially towards fixed contact elements and having radial arms carrying contact buttons on their outer ends to engage said elements. The arms bear on a raised arcuate track when the contact buttons are out of registration with the contact elements, to hold the buttons in an air gap then.

United States Patent 11 1 Grieves et al.

1451 Mar. 5, 1974 STEERING SHAFT, GEAR SHIFT LEVER SWITCH ASSEMBLY [75]lnventorsz Gordon Grieves, Newcastle upon Tyne; Raymond Holmes, Durham,both of England [73] Assignee: Burgess Micro Switch Company,

' Limited, Durham, England [22] Filed: Apr. 19, 1972 [21] Appl. No.:245,446

[30] Foreign Application Priority Data Apr. 19, I972 Great Britain10000/72 [52] US. Cl. 200/6L88, 200/11 E, ZOO/61.54 [51] Int. Cl. I-lOlh21/76 is zoo/61.27, 61.85-61.88, 61.54-61.57;

340/52 R, 52 D, 52 E, 70

[56] References Cited UNITED STATES PATENTS 2,252,489 8/1941 Bluemle200/11 E X 3,121,143

2/1964 Landry et al. ZOO/ll G Primary ExaminerJames R. Scott [5 7]ABSTRACT A rotary switch arrangement may be associated with an automaticgear selector mechanism to inhibit operation of the engine startingcircuit atcertain positions of the mechanism and at other positions tooperate reversing lights and a seat belt warning system. The

switch arrangement comprises a plurality of rotary members 1irgedaxially towards fixed contact elements and having radial arms carryingcontact buttons on their'outer ends to engage said elements. The armsbear on a raised arcuate track when the contact buttons are out ofregistration with the contact elements,

to hold the buttons in an air gap then.

8 Claims, 4 Drawing Figures PATENTEDHAR 51914 3795 7 sum 2 OF 2 STEERINGSHAFT, GEAR SHIFT LEVER SWITCH ASSEMBLY This invention relates toelectrical switches and is concerned more particularly with switches foruse in conjunction with rotary mechanisms, such as in a vehicleautomatic gear selector mechanism to give an electrical switchingfunction in conjunction with the movement of such a mechanism.

An automatic gear selector mechanism is known which is provided with anancillary electrical switching arrangement comprising a plurality offixed contacts embedded in insulating material and a rigid movingcontact arm carrying individual spring-loaded contacts that slide uponthe insulating matrix into and out of engagement with the fixedcontacts. This arrangement can only be used in a low power circuit andif it is to be used, for example, to control a starting motor circuit,it must do this through a relay with the result that the completeinstallation is complex and expensive.

According to the present invention, there is provdied a switch assemblyarranged to be operated by a rotary shaft an comprising a plurality ofcontact elements and at least one switching member rotatable with theshaft, the member comprising contact means arranged to engage thecontact elements at least at one predetermined angular position of theshaft to connect said elements electrically, resilient means arranged toprovide contact pressure between the contact means of the member and thecontact elements, and support menas being provided for the switchingmember to hold the contact means in an air gap when out of engagementwith'the contact. elements. The contact means of the switching membermay comprise a plurality of contacts on respective resilient armsextending outwardly from the axis of said rotation, the, or a part ofthe support means acting on said arms.

Conveniently, the contact elements are arranged at spaced intervalsadjacent the radially outer extend of the switching member and saidsupport means may comprise an arcuate track arranged to bear on a partof the switching member that is disposed radially inwardly of thecontact means. 7

In another preferred feature of the invention, a coil spring acts as theresilient means at an inner annular region of the switching member, aninner support being provided for the member opposite the spring at anannular region radially outside the inner region but remote from theregion of the contact elements.

In the application of the invention to a vehicle automatic gear selectormechanism, at least two contact elements may be associated with astarting circuit of the vehicle engine and the rotary shaft isassociated with a selector lever of the mechanism, the switching memberbeing arranged to permit operation of the starting circuit in aplurality of positions of the shaftlever by virtue of the member havingalternative contact portions for connection of the plurality of contactelements at the different shaft positions.

Also. there may be at least two of said contact element and shown in theaccompamying drawings, wherein:

FIG. I is a transverse sectional view of a switch assembly according tothe invention,

FIGS. 2 and 3 are views of the cover and body, respectively, of theassembly of FIG. 1, with their associated parts, in he directions A-Aand B--B shown in FIG. 1, and

FIG. 4 illustrates schematically the arrangement of the switch assemblyof FIGS. 1 to 3 in conjunction with associated elements of a vehiclehaving an automatic transmission system.

Referring to the drawings, the assembly comprises a moulded insulativecase body 2 and cover 4. A collar 6 extends between aligned apertures inthe body and cover and has a flat sided aperture 8 running through oneend that received a complementary-form end of an operating shaft 58projecting through bore 10 from the automatic gearbox selector unit Sand forming part of an automatic gear selector mechanism, the casingbeing held together and mounted on the unit S using screws or rivets(not shownlthrough holes ll, 12, 1'4, 16(see FIGS. 2 and 3). a

The collar 6 has bearing engagements on a rim 18 of the aperture in thecover 4, through which it projects, and on an annular recess 20 in the'case body 2, in which end flange 22 of the collar seats. The aperture 8forms a keying connection whereby the collar rotates with the operatingshaft.

Switching members 24, 26 of the assembly have ringlike inner regions bywhich they are mounted on a main, generally cylindrical art 28 of thecollar 6 and they are separated by an electrically insulating washer 30bearing on said ring-like regions. Asupplementary ring-like switchingmember 29 is also mounted on the collar part 28 andbears directly on thering-like inner region of the switching member 24. Internal tabs orflats 31 of the three members and of the washer fit slots orcomplementary flats in the collar main part 28 so that the members andthe washer rotate with the collar. A coil spring 32 between the flange22and the member 26 holds the members 24, 26, 29 and the washer 30together and urges them towards the cover 4 on which bearing tracks areprovided for the switching members.

The members 24, 26 are of an electrically conductive material and have aseries of radially extending contact fingers, there being three fingers340 on the member 24 and two fingers 34b on the member 26, each fingerterments associated wtih a reversing light or lights on the vehicle, andthe switching member may then be arranged to connect said elements whenthe rotary shaft is in the reverse gear selection position of the shaftand lever to permit operation of the reversing light then.

The invention will be more particularly described with reference to anembodiment adapted to be incorporated in a vehicle automatic gear-changearrangeminating in a contact button 36a or 36b. The fingers of fingersare co-planer. Pairs of terminals 38a, 38b are mounted in closelyfitting recesses in the cover 4 at spaced angular positions relative tothe axis of the collar, for co-operation with the buttons 36a, 36b. Theswitching member 24 is associated with the terminals 38a and the angularspacing between each adjacent pair of its fingers 34a is the same asthat of the terminals 38a. In two different angular positions of thecollar and shaft, therefore, the two terminals 381: are simultaneouslycontacted by the bottoms of two of the fingers and are thus electricallyconnected by the member 24. Similarly, it is arranged that in anotherangular position a of the collar and shaft the terminals 38b areconnected electrically in the same manner by theswitching member 16. I

an arc of the face of the member adjacent the cover 4, an insert 40 ofconductive material is adhered or moulded to the main body. Resilientcontact arms 42 project from recesses 44 in the cover inner face to havecontact buttons 42a projecting from the recess to be engageable with thearcuate insert 40. The arms 42 are secured in place by rivets 46 whichpass through the cover and secure terminal tabs 48 to the external faceof the cover for connection of the arms 42 to an external circuit. a

By virtue of the insulating body of the member 29, the contact arms 42are isolated from the switching members 24, 26. Also, the permittedmovement of the shaft collar in relation to the terminals 38a, 38b issuch that at no time can the fingers 34b connect the terminals 38a orany two of the fingers 34a connect the terminals 38b. Such a result inrespect of said terminal elements can be achieved either by limiting theangular extent of movement of the collar and shaft or by providingdifferent angular spacings between the terminal elements of each pair.

The cover 4 has an inner bearing track 50 divided into two parts by therecesses 44 and against which the assembly of switching members is urgedby the spring 32. Also, a slightly higher, outer arcuate track 52 isprovided on the cover, this being adjacent the inner ends of theterminals 38a, 38b and being interrupted by the recesses receiving theterminals. The fingers of the switching members 24, 26 bear on the track52 when they are not engaged with the terminals and are thus held withtheir contact buttons spaced from recessed regions 53 on the innersurface of the cover. As is seen in FIG. 1, the terminals 38a, 38b arerecessed below the level of the track 52 but to an extent less than thethickness of the contact buttons, so that as each finger coincides witha terminal the finger is lifted from the track with a degree of flexureand the force of flexure acts to urge the button firmly against thecontacting terminal. In their region of contact with the buttons theterminals have chamfered side faces, as at 54, to allow the contactbuttons to ride freely over them. The preloading of the switchingmembers against the cam track and the terminals simplifies themanufacture of the switching members since then the need for flatness ofthe members is less important and a greater tolerance is accceptable inthis respect.

As indicated in FIG. 4, the switch assembly is mounted on an automaticselector mechanism 56 with its collar 6 engaged by a shaft 58 on whichselector lever 60 of the mechanism is secured so that the switchingmembers are displaced relative to their associated terminals withpivoting of the selector lever. The lever is shown in an end locationthat is associated with the park position of the selector mechanism. Inthis state. the terminals 38:: are connected by the switching member 24so that the member provides an electrical link in starter circuit 62 ofthe vehicle engine thereby allowing the vehicle engine to be started.

Movement of the lever clockwise (as seen in FIG. 4) brings the selectormechanism next to the reverse drive condition. ln'this state, theterminals 38a .are now no longer connected by the member 24 so that theengine cannot be started, while the terminals 38b are connected by theswitching member 26, this making a re- I versing light circuit 64 sothat the reversing lights of the vehicle are switched on automaticallyas the driver selects reverse movement. Further movement of the lever 60disengages the member 26 from the terminals 381; and the lever nextreaches the neutral position in which the member 24 again provides anelectrical link between the terminals 38a of the starter motor circuit.

Pivoting the lever 60 beyond this position brings the selector mechanisminto a'plurality of drive positions at this stage, the contact 42 ofseat belt circuit 66 ar connected by the conductive insert 40 of theswitching member 29 and warning and/or inhibiting means and- /oroperating menas of the seat belt circuit will be actuated in any of thedrive positions. The terminals 38a in the drive position of lever 16will not be connected by the member 24 for reasons aforementioned, i.e.,either the angular movement of the collar is limited or differentangular spacings are provided between the terminal elements of eachpair.

The casing body 2 has a peripheralrim 67 that seats firmly in a recess68 at the edge of the cover. Interruptions 69 of the rim coincide withthe terminal positions so that in conjunction with the recess 68 thereis formed at each such position a recess 70 surrounding the terminal atthe outer face of the casing. The interior of the casing is sealed fromthe exterior by the body and cover being'joined together by an adhesiveseal and the sealing compound also fills the recesses 70. On the collarthere are inner and outer insulative O-rings .72, 74, the outer ringforming a seal between the collar and the cover 4 and the inner ringforming a seal between the collar and the shaft.

The combined effect of the adhesive seal and the 0- rings is that thereis no opportunity for foreign matter to enter the casing from theexterior. There is no need to protect the path between the end flange 22and the body 2 since this lies inside the inner seal 72 and can only bereached fromthe interior of the automatic selector mechanism into whichthe operating shaft.

projects.

What we claim and desire to secure by Letters Patent is:

l. A switch assembly comprising a support mounted v for rotary movementabout a predetermined axis, electrical contact means carried by saidsupport for movement therewith, fixed contact means positioned inrelation to said rotatable support and said movable contact meanscarried thereby for engagement with predetermined of said movablecontact means as said support is rotated about said axis, resilientmeans acting on one of said means for producing a force parallel tosaid-axis and providing thereby contact pressure between said fixed andmovable contact means andadditional means cooperating with said movablecontact means, comprising a plurality of resilient arms extendingoutwardly from the rotary support, for substantially at all timesensuring spatial, contact-free movement of contacts on the ends of saidarms in an air gap during their sojourn toward and until engagement withsaid fixed contact means, said additional means comprising and abutmenton which said resilient arms bear until said contacts of said movablecontact means engage said fixed contact means, said fixed contactmeansbeing positioned at a level for engagement by said contacts of saidmovable contact means and being adapted for lifting, in consequence ofsaid engagement, said movable contact means above the level of saidabutment.

2. A switch assembly according to claim 1 wherein said fixed contactmeans comprise fixed contact elements arranged at spaced arcuateintervals and at predetermined radial distances from said support, saidadditional means comprising an arcuate track on which said movablecontact means bear in a region thereof radially inwardly of saidterminal portion of said movable contact means adapted to engage saidfixed contact means.

3. A switch assembly according to claim 1, wherein said resilient meansis a coil spring bearing on an inner annular region on one side of themovable contact means to urge said movable contact means axially towardsthe fixed contact means, said additional means comprising an innersupport for the movable contact means and being' disposed on theopposite side of the movable contact means and extending along anannular region radially outward of said inner region and remote fromsaid fixed contact means.

4. A switch assembly according to claim 3, wherein the groups of fixedcontact means terminate in contact elements disposed at acommon radialdistance from the rotary support.

5. A switch assembly according to claim 1, wherein said movable contactmeans comprise a plurality of radially extending arms operativelyconnected to the rotary support, groups of said arms being electricallyinsulated from one another, said fixed contact means also being providedas groups for cooperation with said groups of arms.

6. In a vehicle automatic gear selector mechanism having a rotary shaftdisplaceable in conjunction with a selector lever of the mechanism, theimprovement consisting of a switch assembly operatively connected tosaid shaft to be rotatable therewith, said switch assembly comprising asupport operatively connected to said shaft for rotation thereby,movable contact means carried by said support, at least two fixedcontact elemerits adapted for connection in an engine starting circuitfor the vehicle, said fixed contact elements being positioned forengagement by said contact means at a plurality of predetermined angularpositions of the rotary shaft. resilient means acting on the movablecontact means for producing a force parallel to the shaft providingcontact pressure between the movable contact means and the fixed contactmeans, and support means engageable by the movable contact means to holda terminal contact portion of the movable contact means in an air gapwhen 'out of engagement with the fixed contact elements, said movablecontact means comprising a plurality of resilient arms extendingoutwardly from said rotary shaft, said support means comprising anabutment on which said resilient arms bear until contacts on saidterminal portion of said movable contact means engage said fixed contactmeans, said fixed contact means being positioned at a level forengagement by said contacts of said movable contact means and beingadapted for lifting, in consequence of such engagement, said movablecontact means above the level of said abutment.

7. In the assembly according to claim 6, including at least two furtherfixed contact elements associated with a reversing light circuit of thevehicle, said movable contact means including a group of contact armsterminating in contacts engageable with said fixed contact elements whenthe rotary shaft is placed in a reversed gear selection of themechanism, thereby to permit operation of the reversing light.

8. In the switch assembly according to claim 6, including supplementarycontact means of an electrical circuit associated with passenger safetyrestraint means, said supplementary contact means comprising a'fixedpart and a part displaceable with said rotary shaft to render saidcircuit operative at selected settings of the lever.

1. A switch assembly comprising a support mounted for rotary movementabout a predetermined axis, electrical contact means carried by saidsupport for movement therewith, fixed contact means positioned inrelation to said rotatable support and said movable contact meanscarried thereby for engagement with predetermined of said movablecontact means as said support is rotated about said axis, resilientmeans acting on one of said means for producing a force parallel to saidaxis and providing thereby contact pressure between said fixed andmovable contact means and additional means cooperating with said movablecontact means, comprising a plurality of resilient arms extendingoutwardly from the rotary support, for substantially at all timesensuring spatial, contact-free movement of contacts on the ends of saidarms in an air gap during their sojourn toward and until engagement withsaid fixed contact means, said additional means comprising and abutmenton which said resilient arms bear until said contacts of said movablecontact means engage said fixed contact means, said fixed contact meansbeing positioned at a level for engagement by said contacts of saidmovable contact means and being adapted for lifting, in consequence ofsaid engagement, said movable contact means above the level of saidabutment.
 2. A switch assembly according to claim 1 wherein said fixedcontact means comprise fixed contact elements arranged at spaced arcuateintervals and at predetermined radial distances from said support, saidadditional means comprising an arcuate track on which said movablecontact means bear in a region thereof radially inwardly of saidterminal portion of said movable contact means adapted to engage saidfixed contact means.
 3. A switch assembly according to claim 1, whereinsaid resilient means is a coil spring bearing on an inner annular regionon one side of the movable contact means to urge said movable contactmeans axially towards the fixed contact means, said additional meanscomprising an inner support for the movable contact means and beingdisposed on the opPosite side of the movable contact means and extendingalong an annular region radially outward of said inner region and remotefrom said fixed contact means.
 4. A switch assembly according to claim3, wherein the groups of fixed contact means terminate in contactelements disposed at a common radial distance from the rotary support.5. A switch assembly according to claim 1, wherein said movable contactmeans comprise a plurality of radially extending arms operativelyconnected to the rotary support, groups of said arms being electricallyinsulated from one another, said fixed contact means also being providedas groups for cooperation with said groups of arms.
 6. In a vehicleautomatic gear selector mechanism having a rotary shaft displaceable inconjunction with a selector lever of the mechanism, the improvementconsisting of a switch assembly operatively connected to said shaft tobe rotatable therewith, said switch assembly comprising a supportoperatively connected to said shaft for rotation thereby, movablecontact means carried by said support, at least two fixed contactelements adapted for connection in an engine starting circuit for thevehicle, said fixed contact elements being positioned for engagement bysaid contact means at a plurality of predetermined angular positions ofthe rotary shaft, resilient means acting on the movable contact meansfor producing a force parallel to the shaft providing contact pressurebetween the movable contact means and the fixed contact means, andsupport means engageable by the movable contact means to hold a terminalcontact portion of the movable contact means in an air gap when out ofengagement with the fixed contact elements, said movable contact meanscomprising a plurality of resilient arms extending outwardly from saidrotary shaft, said support means comprising an abutment on which saidresilient arms bear until contacts on said terminal portion of saidmovable contact means engage said fixed contact means, said fixedcontact means being positioned at a level for engagement by saidcontacts of said movable contact means and being adapted for lifting, inconsequence of such engagement, said movable contact means above thelevel of said abutment.
 7. In the assembly according to claim 6,including at least two further fixed contact elements associated with areversing light circuit of the vehicle, said movable contact meansincluding a group of contact arms terminating in contacts engageablewith said fixed contact elements when the rotary shaft is placed in areversed gear selection of the mechanism, thereby to permit operation ofthe reversing light.
 8. In the switch assembly according to claim 6,including supplementary contact means of an electrical circuitassociated with passenger safety restraint means, said supplementarycontact means comprising a fixed part and a part displaceable with saidrotary shaft to render said circuit operative at selected settings ofthe lever.